Note carefully: the ideological outlook of these authors is different: Arthur Schlesinger was an American Old Liberal. Pat Buchanan is an American Paleoconservative.

Rod Liddle is a British ex-Labour party supporter who now appears to be a conservative who identifies with the working class. Bruce Bawer seems to be an old-fashioned American liberal, but progressive on many issues.

Yet all of them, broadly speaking, seem to be able to identify serious problems with the development of the modern left, cultural leftism and identity politics.

Of all these books, Rod Liddle’s is the least serious.

Arthur Schlesinger rightly warned of the dangers of Postmodernist multiculturalism, which he correctly saw as very different to the old-fashioned, melting-pot liberal nationalism of America. In his own way, Buchanan warned of the same problem, but with additional emphasis on the destructive aspects of free trade.

Bruce Bawer’s The Victims’ Revolution: The Rise of Identity Studies and the Closing of the Liberal Mind (2012) is an excellent work examining the rise of Postmodernism in the academy and its development into the Social Justice Warrior (or SJW) catastrophe we see today, developments which can be traced to French Poststructuralism and Postmodernism, and their devastating ruination of left-wing intellectual life.

The Illusionist suggests another book:

Lasch, Christopher. 1995. Revolt of the Elites and the Betrayal of Democracy. Norton, New York and London.

Christopher Lasch was a neo-Marxist but turned culturally conservative with a quasi-Marxist economic critique of capitalism, but combined with some unfortunate Freudian psychoanalytic charlatanry and Frankfurt School Marxist nonsense to boot.

Admittedly, I have not read Christopher Lasch’s book in full, but summaries and critical reviews of it (e.g., Rankin 1996), and Lasch’s 1994 article here from Harper’s, suggest that it, too, to a great extent puts its finger on what went wrong with the left.

As Lasch points out:

“In our time … the chief threat seems to come not from the masses but from those at the top of the social hierarchy, the elites who control the international flow of money and information, preside over philanthropic foundations and institutions of higher learning, manage the instruments of cultural production, and thus set the terms of public debate. Members of the elite have lost faith in the values, or what remains of them, of the West. For many people, the very term ‘Western civilization’ now calls to mind an organized system of domination designed to enforce conformity to bourgeois values and to keep the victims of patriarchal oppression—women, children, homosexuals, people of color—in a permanent state of subjection. ….

The industrial working class, once the mainstay of the socialist movement, has become a pitiful remnant of itself. The hope that ‘new social movements’ would take its place in the struggle against capitalism, which briefly sustained the left in the late Seventies and early Eighties, has come to nothing. Not only do the new social movements—feminism, gay rights, welfare rights, agitation against racial discrimination—have nothing in common; their only coherent demand aims at inclusion in the dominant structures rather than at a revolutionary transformation of social relations. ….

The upper middle class, the heart of the new professional and managerial elites, is defined, apart from its rapidly rising income, not so much by its ideology as by a way of life that distinguishes it, more and more unmistakably, from the rest of the population. This way of life is glamorous, gaudy, sometimes indecently lavish. ….

To an alarming extent, the privileged classes—by an expansive definition, the top 20 percent—have made themselves independent not only of crumbling industrial cities but of public services in general. They send their children to private schools, insure themselves against medical emergencies by enrolling in company-supported plans, and hire private security guards to protect themselves against the mounting violence. It is not just that they see no point in paying for public services they no longer use; many of them have ceased to think of themselves as Americans in any important sense, implicated in America's destiny for better or worse. Their ties to an international culture of work and leisure—of business, entertainment, information, and ‘information retrieval’—make many members of the elite deeply indifferent to the prospect of national decline.

The market in which the new elites operate is now international in scope. Their fortunes are tied to enterprises that operate across national boundaries. They are more concerned with the smooth functioning of the system as a whole than with any of its parts. Their loyalties—if the term is not itself anachronistic in this context—are international rather than regional, national, or local. They have more in common with their counterparts in Brussels or Hong Kong than with the masses of Americans not yet plugged in to the network of global communications. ....

The changing class structure of the United States mirrors changes that are taking place all over the industrial world. In Europe, referenda on unification have revealed a deep and widening gap between the political classes and the more humble members of society, who fear that the European Economic Community will be dominated by bureaucrats and technicians devoid of any feelings of national identity or allegiance.”
http://brandon.multics.org/library/Christopher%20Lasch/lasch1994revolt.html

For something written in 1994, this is quite prescient.

We can add to this the generation of Millennials, indoctrinated in cultural leftist nonsense and various SJW cults, who are pathetically and dangerously ignorant of Old Left economic and cultural thought, and whose agenda is – paradoxically – aiding and abetting the catastrophic effects of transnational and globalised neoliberal capitalism.

Even worse, Millennials are so out of touch that many of them are obsessed by the cult of open borders, a policy which would be a wet dream for First World capitalists. Even the Marxists amongst the Millennials seem to be infected and infested with all the insanity of cultural leftism. E.g., your foolish Marxist Millennial who holds a sign with the words “Borders are Racist!” is essentially a tool of neoliberal capitalism.

This is why, if things are to be reversed, the nation-state will come back in a big way soon. National borders, regulated national capitalism, and cultural and civic nationalism – they will need to make a big comeback. To tame the destructive and harmful nature of transnational neoliberal capitalism, you need a powerful national government to make it work for the citizens of each nation. Both transnational corporations and the elites need, for want of a better word, to be made “patriotic” again.

Addendum
I add an interesting video with Rod Liddle relevant to this post:

BIBLIOGRAPHY
Lasch, Christopher. 1994. The Revolt of the Elites: Have they Canceled their Allegiance to America?,” Harper’s Magazine (November) 289.1734: 39–49.
http://brandon.multics.org/library/Christopher%20Lasch/lasch1994revolt.html

Rankin, Aidan. 1996. “Christopher Lasch and the Moral Agony of the Left,” New Left Review 0.215 (January 1): 149–155.

“Lasch never became a Cold Warrior, in contrast to those of his peers who migrated from Partisan Review to some form or other of neoconservatism. Nor did he ever blunt his critique of economic and political centralization and the technological rationality that sustained them: unlike Irving Kristol, he was not prepared to muster even one cheer for capitalism.” (p. 330).---------------That is part of the forgotten story of Neoconservatism, surely the most poisonous element of American political life today. People forget how the first generation Neconservatives were Trotskyists or Marxists.

Also:

“After The Minimal Self, Lasch drifted away from Freud, Marx, and their Frankfurt School interpreters. His break with the cultural Left also became more thorough and more obvious. In the 1960s and 1970s he had been a frequent contributor to organs of Left opinion like the Nation and the New York Review of Books, …. The postmodern Left irritated him, and the feeling was mutual.” (p. 339).

I would also suggest Thomas Frank's "Listen Liberal: Or, What Ever Happened to the Party of the People?"

Frank's book is specifically about the U.S. Democratic Party and it discusses the transformation of the party from a broad working person's party to one dominated by affluent professionals and focused on social/cultural liberalism and identity politics as opposed to "kitchen table" economic issues. I would not be surprised if the issues he discusses also apply to the U.K. Labour Party and other center-left parties, though.

While Frank is not socially conservative he definitely sees through the attempt to redefine Leftism as an ideology almost solely concerned with social/cultural and identity issues.

I've noticed that you've used the word 'patriotic' in a few posts reluctantly. Do you fundamentally disagree with patriotism or do you just not like what it's currently associated with (such as right wing movements)? (Kind of like how some conservative-minded people may avoid calling themselves conservative because they don't want to be associated with market fundamentalism.)